net: render 'metric' values in per-subnet routes

It is possible to have a metric value in a per-subnet route.
This is currently missing in all renderers.  Update each
renderer to emit the correct metric value from the config.

LP: #1805871

3 files changed, 39 insertions, 21 deletions

diff --git a/cloudinit/net/eni.py b/cloudinit/net/eni.py
index c6f631a9..64236320 100644
--- a/cloudinit/net/eni.py
+++ b/cloudinit/net/eni.py
@@ -371,22 +371,23 @@ class Renderer(renderer.Renderer):
             'gateway': 'gw',
             'metric': 'metric',
         }
+
+        default_gw = ''
         if route['network'] == '0.0.0.0' and route['netmask'] == '0.0.0.0':
-            default_gw = " default gw %s" % route['gateway']
-            content.append(up + default_gw + or_true)
-            content.append(down + default_gw + or_true)
+            default_gw = ' default'
         elif route['network'] == '::' and route['prefix'] == 0:
-            # ipv6!
-            default_gw = " -A inet6 default gw %s" % route['gateway']
-            content.append(up + default_gw + or_true)
-            content.append(down + default_gw + or_true)
-        else:
-            route_line = ""
-            for k in ['network', 'netmask', 'gateway', 'metric']:
-                if k in route:
-                    route_line += " %s %s" % (mapping[k], route[k])
-            content.append(up + route_line + or_true)
-            content.append(down + route_line + or_true)
+            default_gw = ' -A inet6 default'
+
+        route_line = ''
+        for k in ['network', 'netmask', 'gateway', 'metric']:
+            if default_gw and k in ['network', 'netmask']:
+                continue
+            if k == 'gateway':
+                route_line += '%s %s %s' % (default_gw, mapping[k], route[k])
+            elif k in route:
+                route_line += ' %s %s' % (mapping[k], route[k])
+        content.append(up + route_line + or_true)
+        content.append(down + route_line + or_true)
         return content
 
     def _render_iface(self, iface, render_hwaddress=False):
diff --git a/cloudinit/net/netplan.py b/cloudinit/net/netplan.py
index bc1087f9..21517fda 100644
--- a/cloudinit/net/netplan.py
+++ b/cloudinit/net/netplan.py
@@ -114,13 +114,13 @@ def _extract_addresses(config, entry, ifname):
             for route in subnet.get('routes', []):
                 to_net = "%s/%s" % (route.get('network'),
                                     route.get('prefix'))
-                route = {
+                new_route = {
                     'via': route.get('gateway'),
                     'to': to_net,
                 }
                 if 'metric' in route:
-                    route.update({'metric': route.get('metric', 100)})
-                routes.append(route)
+                    new_route.update({'metric': route.get('metric', 100)})
+                routes.append(new_route)
 
             addresses.append(addr)
 
diff --git a/cloudinit/net/sysconfig.py b/cloudinit/net/sysconfig.py
index 9c16d3a7..17293e1d 100644
--- a/cloudinit/net/sysconfig.py
+++ b/cloudinit/net/sysconfig.py
@@ -156,13 +156,23 @@ class Route(ConfigMap):
                                            _quote_value(gateway_value)))
                     buf.write("%s=%s\n" % ('NETMASK' + str(reindex),
                                            _quote_value(netmask_value)))
+                    metric_key = 'METRIC' + index
+                    if metric_key in self._conf:
+                        metric_value = str(self._conf['METRIC' + index])
+                        buf.write("%s=%s\n" % ('METRIC' + str(reindex),
+                                               _quote_value(metric_value)))
                 elif proto == "ipv6" and self.is_ipv6_route(address_value):
                     netmask_value = str(self._conf['NETMASK' + index])
                     gateway_value = str(self._conf['GATEWAY' + index])
-                    buf.write("%s/%s via %s dev %s\n" % (address_value,
-                                                         netmask_value,
-                                                         gateway_value,
-                                                         self._route_name))
+                    metric_value = (
+                        'metric ' + str(self._conf['METRIC' + index])
+                        if 'METRIC' + index in self._conf else '')
+                    buf.write(
+                        "%s/%s via %s %s dev %s\n" % (address_value,
+                                                      netmask_value,
+                                                      gateway_value,
+                                                      metric_value,
+                                                      self._route_name))
 
         return buf.getvalue()
 
@@ -370,6 +380,9 @@ class Renderer(renderer.Renderer):
                     else:
                         iface_cfg['GATEWAY'] = subnet['gateway']
 
+                if 'metric' in subnet:
+                    iface_cfg['METRIC'] = subnet['metric']
+
                 if 'dns_search' in subnet:
                     iface_cfg['DOMAIN'] = ' '.join(subnet['dns_search'])
 
@@ -414,15 +427,19 @@ class Renderer(renderer.Renderer):
                         else:
                             iface_cfg['GATEWAY'] = route['gateway']
                             route_cfg.has_set_default_ipv4 = True
+                    if 'metric' in route:
+                        iface_cfg['METRIC'] = route['metric']
 
                 else:
                     gw_key = 'GATEWAY%s' % route_cfg.last_idx
                     nm_key = 'NETMASK%s' % route_cfg.last_idx
                     addr_key = 'ADDRESS%s' % route_cfg.last_idx
+                    metric_key = 'METRIC%s' % route_cfg.last_idx
                     route_cfg.last_idx += 1
                     # add default routes only to ifcfg files, not
                     # to route-* or route6-*
                     for (old_key, new_key) in [('gateway', gw_key),
+                                               ('metric', metric_key),
                                                ('netmask', nm_key),
                                                ('network', addr_key)]:
                         if old_key in route: